High-speed moving vehicles develop rapidly in China and all over the world. For example, the high-speed moving vehicles include a high-speed railway train, a magnetic levitation train, and a metro. The high-speed railway train is used as an example. Operating mileage of the high-speed railway train is over 30000 kilometers and is increasing rapidly. Many high-end persons frequently take the high-speed moving vehicles for a long time, and the high-speed moving vehicles require information-based construction. Therefore, there is an ever-increasing communication requirement of the high-speed moving vehicles.
However, the high-speed moving vehicles are different from conventional indoor and outdoor mobile communications scenarios. Because a train is moving at a high speed, a train body has a large penetration loss, scenes and terrains are complicated and varied, and the like, a current public network is not suitable for providing services for users taking the high-speed moving vehicles. Therefore, it is increasingly urgent to establish a dedicated network that provides a service for users taking high-speed moving vehicles. For example, currently there are equipment vendors and operators that have begun to plan and deploy such a high-speed railway dedicated wireless network (referred to as a “high-speed railway dedicated network” in the following). The high-speed railway dedicated network covers an ongoing journey of a high-speed railway train and areas near a platform of the high-speed railway station. Cell deployment in a high-speed railway station area is shown in FIG. 1A. Dedicated network cells of the high-speed railway station within coverage of a high-speed railway dedicated network 106 include an indoor distributed cell and a platform cell. Both a waiting room 102 and an entrance and exit passageway 103 belong to the indoor distributed cell 101. A platform 104 belongs to the platform cell. A public network cell 105 covers a railway station square outside the railway station. Currently, the dedicated network cell and the public network cell are individually deployed during high-speed railway network planning. In consideration of line-type coverage of a railway, a solution of cell cascading and continuous coverage is used for the high-speed railway dedicated network, as shown in FIG. 1B. In the example of FIG. 1B, a high-speed railway track area is continuously covered by cascaded dedicated network cells 111, and public network cells 115 also cover the high-speed railway track area.
The public network and the high-speed railway dedicated network use the following cooperation principles:
(1) In most areas of a high-speed railway (for example, on an ongoing journey of a high-speed railway train), a neighboring cell relationship is not mutually configured between a high-speed railway dedicated network cell and a surrounding public network cell. That is, only a cascaded cell in the dedicated network is configured as a neighboring cell of the dedicated network cell, and no public network cell is configured as a neighboring cell of the dedicated network cell; and no dedicated network cell is configured as a neighboring cell of the public network cell.
(2) A mutual neighboring cell relationship is configured, between a public network cell and a dedicated network cell, near the platform of the railway station, so that first-type UE accesses a dedicated network cell (such as the dedicated network cell 101 in FIG. 1A) from a public network cell (such as the public network cell 105 in FIG. 1A), or accesses a public network cell from a dedicated network cell.
On an ongoing journey of a high-speed railway train, because there is no mutual neighboring cell relationship between a high-speed railway dedicated network cell and a surrounding public network cell, user equipment (UE for short) in an idle state cannot access another type of network cell (such as the dedicated network cell 111 in FIG. 1B) from one type of network cell (such as the public network cell 115 in FIG. 1B) by performing cell reselection, and the UE in a connected state cannot be handed over to another type of network cell by performing a handover procedure. Therefore, on an ongoing journey of a high-speed moving vehicle, when UE is detached from a communications network of the high-speed moving vehicle due to an exception and accesses a public network, the UE cannot subsequently return to the communications network of the high-speed moving vehicle in the prior art, and this affects user experience of a user taking the high-speed moving vehicle.